/Engine/Plugins/Animation/ControlRig/Source/ControlRig/Public/Rigs/RigHierarchy.h
Returns the event fired during undo / redo
[FRigHierarchyUndoRedoTransformEvent](API\Plugins\ControlRig\Rigs\FRigHierarchyUndoRedoTransformEv-) & OnUndoRedo()